perf inject: Set PERF_RECORD_MISC_BUILD_ID_SIZE

With perf inject -b, it synthesizes build-id event for DSOs.  But it
missed to set the size and resulted in having trailing zeros.

As perf record sets the size in write_build_id(), let's set the size
here as well.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221119002750.1568027-1-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/synthetic-events.c

@@ -2218,8 +2218,9 @@ int perf_event__synthesize_build_id(struct perf_tool *tool, struct dso *pos, u16
 	len = pos->long_name_len + 1;
 	len = PERF_ALIGN(len, NAME_ALIGN);
 	memcpy(&ev.build_id.build_id, pos->bid.data, sizeof(pos->bid.data));
+	ev.build_id.size = pos->bid.size;
 	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
-	ev.build_id.header.misc = misc;
+	ev.build_id.header.misc = misc | PERF_RECORD_MISC_BUILD_ID_SIZE;
 	ev.build_id.pid = machine->pid;
 	ev.build_id.header.size = sizeof(ev.build_id) + len;
 	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);